Australian Energy Market Operator

AEMO operates Australia's National Electricity Market (NEM), the interconnected power system in Australia’s eastern and south-eastern seaboard, and the Wholesale Electricity Market (WEM) and power system in Western Australia.

AEMO operates gas retail markets in New South Wales and the Australian Capital Territory, Queensland, South Australia, Victoria, and Western Australia. AEMO also operates wholesale gas markets in south-eastern Australia, those being the Declared Wholesale Gas Market in Victoria (DWGM), the Short Term Trading Market in Adelaide, Brisbane and Sydney (STTM), and the Gas Supply Hub (GSH), whose trading locations are based at Wallumbilla in Queensland, and Moomba in South Australia. AEMO also operates the Natural Gas Services Bulletin Board (GBB), and is system operator of the Victorian Gas Declared Transmission System. AEMO is also responsible for Gas Services Information functions in Western Australia.

Planned outage of Tailem Bend - South East 275kV No 2 line in the SA region on 02/06/2018

AEMO ELECTRICITY MARKET NOTICE

The Tailem Bend - South East 275kV No 2 line in South Australia (SA) region is planned to be out of service from 0930 hrs to 1330hrs on 02/06/2018.

During this outage, SA will remain connected to the rest of the NEM via the Tailem Bend - South East 275kV No 1 line and the 132kV network.

A credible contingency event on the Tailem Bend - South East 275kV No 1 line during this planned outage will sever the 275kV connections between the NEM and SA. If SA remains connected to the NEM via the 132kV network, this will pose a system security issue.

If one of the above credible contingencies occurs, 35 MW of raise and lower regulation FCAS will be sourced from within SA.

If this occurs, AEMO will take all necessary steps as outlined in Section 6.1 of SO-OP-3715 Power System Security Guideline to separate the 132kV network and therefore manage an orderly separation of SA from the NEM.

Mya SanAEMO Operations

6288921 May 2018 11:39GENERAL NOTICE

Planned outage of South East - Heywood No 2 275 kV line in the SA region on 19/06/2018

The South East - Heywood No 2 275 kV line in the South Australia (SA) region is planned to be out of service from 0800 hrs to 1700 hrs on 19/06/2018.

A credible contingency event during this planned outage could cause synchronous separation of the South Australia (SA) region from the rest of the NEM. If separation occurs, load may be interrupted due to the operation of the Automatic Under Frequency Load Shedding (AUFLS) scheme in SA.

The credible separation contingency is managed as follows:

- 35 MW of raise and lower regulation FCAS will be sourced from SA. -When power transfer is from SA to Victoria, contingency lower FCAS will be sourced from SA. -When power transfer is from Victoria to SA, due to the 47-52Hz island separation frequency band advised by the SA jurisdiction, contingency raise FCAS is not sourced in SA and the AUFLS scheme may respond to low frequency events. -Power transfer will be restricted on Victoria - South Australia interconnector (Heywood interconnector) to manage system security following the loss of the next contingency.

Forecast capacity reserves in the SA region are currently sufficient to meet electricity demand during the planned outage.

The following constraint sets have been invoked for this outage: F-I-HYSE I-HYSE I-VS_050 S-HYSE_BC-2CP S-X_BC_CP V-HYTS_M12

Refer AEMO Network Outage Schedule (NOS) for further details.

Mya SanAEMO Operations

6288721 May 2018 11:37GENERAL NOTICE

Planned outage of South East - Heywood No 1 275 kV line in the SA region on 18/06/2018

The South East - Heywood No 1 275 kV line in the South Australia (SA) region is planned to be out of service from 0800 hrs to 1700 hrs on 18/06/2018.

A credible contingency event during this planned outage could cause synchronous separation of the South Australia (SA) region from the rest of the NEM. If separation occurs, load may be interrupted due to the operation of the Automatic Under Frequency Load Shedding (AUFLS) scheme in SA.

The credible separation contingency is managed as follows:

- 35 MW of raise and lower regulation FCAS will be sourced from SA. -When power transfer is from SA to Victoria, contingency lower FCAS will be sourced from SA. -When power transfer is from Victoria to SA, due to the 47-52Hz island separation frequency band advised by the SA jurisdiction, contingency raise FCAS is not sourced in SA and the AUFLS scheme may respond to low frequency events. -Power transfer will be restricted on Victoria - South Australia interconnector (Heywood interconnector) to manage system security following the loss of the next contingency.

Forecast capacity reserves in the SA region are currently sufficient to meet electricity demand during the planned outage.

The following constraint sets have been invoked for this outage: F-I-HYSE I-HYSE I-VS_050 S-HYSE_BC-2CP S-X_BC_CP V-HYTS_M12

Refer AEMO Network Outage Schedule (NOS) for further details.

Mya SanAEMO Operations

6288420 May 2018 13:11GENERAL NOTICE

Possible intervention to manage power system security in South Australia (SA) Region

AEMO ELECTRICITY MARKET NOTICE

The synchronous generating units expected to be synchronised in SA from 0030 hrs 21/05/18 to 1330 hrs 22/05/18 in Pre-dispatch published at 1300 hrs 20/05/18 are inadequate to maintain sufficient system strength in SA and hence a secure operating state.

AEMO currently estimates that, in the absence of sufficient market response by 1400 hrs 20/05/18, AEMO may need to intervene by issuing a direction requiring one or more SA synchronous generating unit(s) to operate or remain synchronised from 0030 hrs 21/05/18 to 1330 hrs 22/05/18, to maintain power system security in SA.

An AEMO Intervention Event occurred when AEMO issued a direction to maintain the power system in a secure operating state.

The AEMO Intervention Event commenced in the 2305 hrs dispatch interval and is forecast to apply until 0030 hrs 21/05/2018.

AEMO declares all dispatch intervals during the AEMO Intervention Event to be intervention price dispatch intervals.

The direction is expected to affect dispatch quantities for intervention pricing purposes from the 0035 hrs dispatch interval on 20/05/2018.

Manager NEM Real Time Operations

6288219 May 2018 23:02MARKET INTERVENTION

Direction - South Australia region 19/05/2018

AEMO ELECTRICITY MARKET NOTICE.

Direction - South Australia region 19/05/2018

In accordance with section 116 of the National Electricity Law, AEMO has issued a direction to a participant in the South Australia region.

The direction was necessary to maintain the power system in a secure operating state.

AEMO may issue or revoke additional directions in order to meet the current requirement, unless sufficient market response is provided.

A further market notice will be issued when all directions related to this requirement have been cancelled.

For the purposes of the National Electricity Rules this is a direction under clause 4.8.9(a).

Manager NEM Real Time Operations

6288019 May 2018 13:04GENERAL NOTICE

Possible intervention to manage power system security in South Australia (SA) Region

AEMO ELECTRICITY MARKET NOTICE

The synchronous generating units expected to be synchronised in SA from 0030 hrs 20/05/18 in Pre-dispatch published at 1300 hrs 19/05/18 are inadequate to maintain sufficient system strength in SA and hence a secure operating state.

AEMO currently estimates that, in the absence of sufficient market response by 2300 hrs 19/05/18, AEMO may need to intervene by issuing a direction requiring one or more SA synchronous generating unit(s) to operate or remain synchronised from 0030 hrs 20/05/18, to maintain power system security in SA.

Manager NEM Real Time Operations

6287818 May 2018 17:28CONSTRAINTS

Updated generator combinations for SA system strength

AEMO MARKET NOTICE

Updated generator combinations for SA system strength

AEMO is continuing to investigate system strength requirements in South Australia.

Through this work, AEMO has identified ten additional generator combinations which meet minimum system strength requirements in South Australia.

The following combinations have been relabelled:LOW_18 is now LOW_18ALOW_17A is now LOW_17LOW_20A is now LOW_20

For more information refer to the updated limits advice:https://www.aemo.com.au/-/media/Files/Electricity/NEM/Security_and_Reliability/Congestion-Information/2018/Transfer-Limit-Advice---South-Australian-System-Strength.pdf

A further update to this advice is planned before the end of June 2018.